Asthma: Causes, Triggers, and Why It's Not Contagious

Asthma is a chronic inflammatory disease of the airways, not an infection. It cannot be spread from person to person like a cold or flu.

Underlying Causes (Multifactorial)

• Genetics: Family history of asthma, atopy (eczema, allergic rhinitis).
• Environmental exposures: Early-life respiratory infections (RSV), tobacco smoke, air pollution, occupational irritants.
• Immune dysregulation: Th2-mediated inflammation, IgE sensitization to allergens.

Common Triggers (Provoke Symptoms, Not Cause Disease)

• Allergens: dust mites, pollen, mold, pet dander, cockroach.
• Irritants: smoke, strong odors, cold air, pollution.
• Exercise (exercise-induced bronchoconstriction).
• Respiratory infections (viruses).
• Emotions (stress, laughter), certain medications (NSAIDs, beta-blockers in sensitive individuals).

Pathophysiology

• Airway inflammation → bronchial hyperresponsiveness → bronchoconstriction, mucus hypersecretion, edema.
• Symptoms: wheeze, cough, chest tightness, dyspnea (variable, reversible).

Management

• Controller meds (inhaled corticosteroids) treat inflammation.
• Reliever meds (SABA) for acute symptoms.
• Trigger avoidance, asthma action plan, regular review.

Asthma is controllable. With proper treatment, most people live full, active lives.